title: Photopatterned anisotropic swelling of dual-crosslinked hyaluronic acid hydrogels.
abstract: The purpose of a tissue engineered (TE) scaffold is to provide a support structure that can aid the regeneration of damaged tissue. Unlike native tissues, currently existing TE scaffolds are structurally simple, with homogeneous bulk properties that are unable to induce cells to regenerate architecturally complex healthy tissue. Thus, there is a need for methods that can create structural complexity within TE scaffolds to guide tissue regeneration. In this paper we have engineered novel dual-crosslinked hyaluronic acid hydrogel scaffolds with photopatterned anisotropic swelling. Anisotropic swelling can produce zonal distributions of crosslink density, water content and viscoelasticity on the macro- and micro-scales within the hydrogel scaffold. We have found that anisotropically swelling hydrogels can be obtained by a combination of chemical crosslinks and patterned photocrosslinks within a single dual-crosslinked hydrogel. According to our method an unswollen chemically crosslinked hydrogel substrate was spatially patterned with photocrosslinks that restricted swelling at selected sites. The resulting dual-crosslinked hydrogel swelled anisotropically because of differential crosslink densities between the photopatterned and non-photopatterned regions. Anisotropic swelling permitted the hydrogel to contort and evolve a shape different from that of the unswollen hydrogel. A biodegradable hydrogel with this unique swelling behavior yields a new, unexplored type of shape-changing TE scaffold.
authors.affiliation: Department of Chemical Engineering, The University of Texas at Austin, 1 University Station C0400, Austin, Texas 78712, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Zawko
authors.forename: Shalu
authors.initials: S
authors.lastname: Suri
authors.forename: Quan
authors.initials: Q
authors.lastname: Truong
authors.forename: Christine E
authors.initials: CE
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D016880:Anisotropy; D001672:Biocompatible Materials / Q000737:chemistry*; D002417:Cattle; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D004548:Elasticity; D006820:Hyaluronic Acid / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D020100:Hydrogels / Q000032:analysis / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods; D012212:Rheology / Q000379:methods; D018502:Streptococcus equi; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006820:Hyaluronic Acid